12v inverter for laptop?

midlf · Oct 9, 2006

If your laptop power supply is rated for multiple voltages and frequencies it is most likely a high frequency chopper power supply and is not fussy about it's input waveform. I would not hesitate to use mine on a standard 120Vac inverter. That said I have not tried mine but, as stated, would not hesitate.

gotrocks · Oct 10, 2006

Thanks to ALL for the replies. My confusion is that my understanding of watts = volts x amps. My power box that came with Dell Inspiron 1100 has the same listing as randy41. Now if watts = volts X amps then
1.5 amps x 110 volts = 165 watts. I have looked at several from 90 watts, to 140 watts on up to 400 watts. They all say "power laptop computers".
When I questioned the sales person today and ask what would happen if I purchased the 140 watt unit and plugged in 165 watt appliance, he said "It will burn it up." I'm still shopping. Thank again for all replies.

"Don't sit under the apple tree with anyone...." when a thunderstorm approaches or you both may get inverted.

We don't watt that to happen.

rich_ncal · Oct 10, 2006

My laptop has a 65watt 18.5v supply. I assume the 65watts is the max output during battery charging while the computer is on and most of the time it takes less power to run the computer.

I would think a well designed power supply would include internal limiting and at a maximum output current it start to droop or lower in output voltage above that maximum current output. The voltage would decrease until it turns off or a breaker would trip.

It would have to be a very poor quality design to just blow up. It often happens that an inverting power supply is over loaded. They are pushed hard in many applications.

shvl73 · Oct 11, 2006

I'm looking at the power adapter on my Averatec as I type. It states 100-240V~ 1.6A 50-60HZ.
Output: 19V 3.42A.
The inverter from Sams Club is 100W and has worked well.

gotrocks · Oct 11, 2006

Thanks again to All. I found a Black/Decker today.
The box indicates and I quote 200 WATT powers up to 1.74 amps.
Haven't tried it yet, will yell

if it does not run my 1.5 amp laptop.

hayden · Oct 13, 2006

gotrocks said:
Thanks to ALL for the replies. My confusion is that my understanding of watts = volts x amps. My power box that came with Dell Inspiron 1100 has the same listing as randy41. Now if watts = volts X amps then
1.5 amps x 110 volts = 165 watts. I have looked at several from 90 watts, to 140 watts on up to 400 watts. They all say "power laptop computers".
When I questioned the sales person today and ask what would happen if I purchased the 140 watt unit and plugged in 165 watt appliance, he said "It will burn it up." I'm still shopping. Thank again for all replies.

"Don't sit under the apple tree with anyone...." when a thunderstorm approaches or you both may get inverted.
We don't watt that to happen.

If you are looking at an iGo that will replace the laptop power supply, use the power supply OUTPUT voltage/amps to determine the iGo capacity. Most laptop supplies are 70-90 watts.

If you are looking for an inverter to power your existing power supply, then look at the INPUT power requirements (the numbers you quoted) when sizing the inverter.

Keep in mind that you will get much better effeciency (read car battery life assuming you are running on the batteries) usung the iGo because you are only doing one power conversion step (DC to DC). With the inverter and existing AC adapter you are doing two conversions (DC to AC, then AC back to DC). Both approaches will work.